Field of the Invention
The present invention relates to image encoding and decoding, and more particularly, to a method for predicting, and encoding and decoding an image of a higher layer by using information of a lower layer in image encoding and decoding in a multi-layer structure.
Related Art
In recent years, while a multimedia environment has been built up, various terminals and networks have been used and the resulting use requirement has been diversified.
For example, as a performance and a computing capability of a terminal have been diversified, a supported performance has also been diversified for each apparatus. Further, in the case of a network in which information is transmitted, a pattern, an information amount, and a transmission speed of the transmitted information, as well as an external structure such as wired and wireless networks have been diversified for each function. A user has selected a terminal and a network to be used according to a desired function and further, spectrums of a terminal and a network which an enterprise provides to the user have been diversified.
In this regard, in recent years, as a broadcast having a high definition (HD) resolution has been extended and serviced worldwide as well as domestically, a lot of users have been familiar with a high definition image. As a result, a lot of image service associated organizations have made a lot of efforts to develop a next-generation image apparatus.
Further, with an increase in interest in ultra high definition (UHD) having four times higher resolution than an HDTV as well as the HDTV, a requirement for technology that compresses and processes a higher resolution and higher definition image has been further increased.
In order to compress and process the image, inter prediction technology of predicting a pixel value included in a current image from a temporally prior and/or post image, intra prediction technology of predicting another pixel value included in the current image by using pixel information in the current image, and entropy encoding technology of allocating a short sign to a symbol in which an appearance frequency is high and a long sign to a symbol in which the appearance frequency is low, and the like may be used.
As described above, when respective terminals and networks having different supported functions, and the diversified user requirements are considered, a quality, a size, a frame, and the like of a supported image need to be consequently diversified.
As such, due to heterogeneous communication networks, and terminals having various functions and various types of terminals, scalability that variously supports the quality, resolution, size, frame rate, and the like of the image becomes a primary function of a video format.
Accordingly, it is necessary to provide a scalability function so as to achieve video encoding and decoding in terms of time, space, image quality, and the like in order to provide a service required by the user under various environments based on a high-efficiency video encoding method.